Sound impedance joint for torpedo



April 4, 1961 T. v. BLAKE 2,977,919

SOUND IMPEDANCE JOINT FOR TORPEDO Filed May 28, 1954 awn- INVENTOR. THEODORE V. BLAKE ATTORNEY United States Patent 1 9 1 2 9. r 1 SOUND IMPEDANCE JOINT non TORPEDO Theodore vV. Blake, Pasadena, assignor to the United States of America as represented by the SecretaryoftheNavy Filed May 28, 1954, s m, 433,316

' .1 C a (C1,- 1.1 77

(Granted under 'h'tle as, Us. Code 1952 mi 2 The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

This invention relates to torpedoes and more particularly to torpedo shell sound impedance joints. 7 In torpedoes equipped with sonar guidance equipment it is desirable that the transmission of noise carried through a torpedo shell from the propulsion apparatus, usually disposed at the rearward portion of the torpedo, be minimized .to obviate interference with guidance signals received by its sonar equipment and to attain this end, it has been the practice to provide sound impedance joints in torpedo shells. In one form of joint, rubber-like washers have been disposed between shell sections, but with sacrifice of strength at the joints. Metals of chemical composition, differing from the shell, and differing from each other where a plurality are employed (mismatching) have been similarly employed and, while stronger than the rubber construction, are not as effective in impeding transmission of noise. With either of the constructions referred to, the inside diameter of a torpedo has been undesirably reduced rendering difficult the installation of desired larger internal components.

Principal objects of this invention are to provide a torpedo shell sound impedance joint which minimizes transfer of noise between adjacent shell sections, is strong in construction and does not objectionably reduce the inside shell diameter at the joint.

Other objects are to provide a sound impedance joint which is simple in construction and assembly, economical of manufacture, and having improved efliciency in reducing transmission of noise.

Still further objects, advantages, and salient features will become more apparent from the description to follow, the appended claims, and the accompanying drawing, in which:

Fig. 1 is a side elevation of a torpedo embodying the invention;

Fig. 2 is an enlarged section taken on line 2-2, Fig. 1;

Fig. 3 is a section taken on line 3-3, Fig. 2; and

Fig. 4 is an enlarged section of the sound impedance ring shown in Figs. 2 and 3.

Referring in detail to the drawing, torpedo T is of any conventional construction comprising a plurality of shell sections 10, 11, 12, 13, 14 which are secured together and between which it is desired to impede transmission of noise, as for example, between tail section 14 and nose section 10.

Referring to Figs. 2 to 4, sections 11, 12 are cylindrical tubes having adjacent confronting annular end faces 11a, 12a, respectively, secured together by a plurality of angularly'spaced machine screws 15, and between which faces a joint ring R, forming the subject of the invention, is disposed.

Sound impedance ring R is provided with one or more axially spaced metallic reinforcing rings 16 imbedded 2,977,919 Fatented Apr. 4, 1961 ice Q in a rubber-like material, such as Fairprene rubber this rubber having interspersed voids 17. Angularly spaced apertures 18 extend between the end faces of the impedance ring and its reinforcing ring portion, through which screws 15 extend, these being out of contact with the reinforcing rings. Any suitable fabric-like material 19 may be employed to'reinforce the rubber-like mate rial.

In one mode 'of construction, strips of fabric, impregnated with uncured Fairprene rubber, are flipped about-a reinforcing ring, as understood in the power transmission belt art, in one or more layers, two being illustrated in Fig. 4, and a plurality of same stacked together, two of these also being illustrated, the built up unit then being suitably cured in a mold under elevated temperature and pressure. a

In the preferred form of the invention illustrated, shell 12 is provided with an internal flange 20 which engages the major portion of the inner surface of ring R, this adding strength to the joint.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. In a torpedo having an outer shell with adjacent axially aligned tubular sections secured together with a transverse joint therebetween disposed substantially in a plane perpendicular to the axis of said sections, the improvements in combination therewith, comprising; an annular sound impedance ring unit, forming a portion of the joint, disposed between adjacent annual ends of said sections, said unit being formed of rubber-like material having at least one relatively rigid reinforcing ring embedded therein, and angularly spaced apertures extending between opposite faces of the unit and through the reinforcing ring, for receiving section fastening members adapted to engage both sections.

2. Apparatus in accordance with claim 1 wherein said rubber-like material is interspersed with voids.

3. Apparatus in accordance with claim 1 wherein said rubber-like material is reinforced with fabric.

4. Apparatus in accordance with claim 3 wherein said rubber-like material is interspersed with voids.

5. Apparatus in accordance with claim 1 wherein the walls of the apertures in the reinforcing ring are each spaced from the fastening member extending therethrough to render the latter out of contact with the former.

6. Apparatus in accordance with claim 1 wherein one of said sections is provided with a flange engaging a circular surface of said unit, said flange being out of contact with the adjacent section.

7. Apparatus in accordance with claim 6 wherein said flange engages an inner circular surface of said unit.

8. Apparatus in accordance with claim 7 wherein said rubber-like material is reinforced with fabric andinterspersed with voids, and the walls of the apertures in member extending therethrough to render the latter out of contact'with the former.

9. A torpedo having an outer shell including adjacent axially aligned sections having confronting annular ends of substantially the same outer diameter, the end surface of one of said sections being disposed in a plane perpendicular to the longitudinal axis of the sections, and the end surface of the other section being spaced from and parallel to the first named end surface, thereby forming a space between the end surfaces, said other section including a circular flange projecting toward said one of said sections substantially closing the inner periphery 1 of saici space, sound imyecling material ciisposeii within said space, and means extending through said material and across said space and engaging both sections securing same together. d v k, 10. A terpedo in accordance with claim '9 wherein said material is rubber-like and comprises an anmilar rein- References Cited in tire file oi this patent UNITED STATES PATENTS forcing ringvimbdded therein, spaced aperture exte'n'd- 'ing between oppositefaces qf the material aridthroughv 1 the reinforcing ring, said'means engaging both sections.

4 Mean? Aug. 15, 1916 Kuhn NQV; 3, 1936 Austin Dec.v 26,v 1939 i Daly 1 Aug. 18, 1959 TGREIGN #ATENTS 

